IKEA Stoughton, which opened in 2005 at 357,000 square feet, will grow to about 416,000 square feet. Construction is expected to commence this fall, with a planned completion date of fall 2014. The store will remain open during construction, maintaining its full product offering, company executives said.

“IKEA is thrilled with the success of Stoughton,” said Frank Briel, store manager, in a statement. “But as its customers and sales continue to grow... the size of the store’s warehouse..is less than ideal.”

Under the plan, IKEA will expand its self-serve furniture section where shoppers collect flat-packed items, rearranging customer service functions to the new part of the store and enlarging the home delivery area. This extension will blend into the existing structure so the store can maintain the unique architectural design for which IKEA stores are known, the company said.

Located on 27 acres along Route 24, IKEA has 50 room-settings, three model home interiors, a supervised children’s play area, and a 350-seat restaurant.

Last year, IKEA shelved its longtime plan to build a second Bay State store at Assembly Square in Somerville. In a letter to the city at the time, IKEA’s real estate manager Doug Greenholz said the company was abandoning plans for a 340,000-square-foot store. He wrote that Stoughton has “surpassed our expectations for attracting customers from throughout the region...that the immediate needs of our Boston-area customers are being served effectively by the existing Stoughton store and that a second Boston-area location is not needed for the foreseeable future.”